When attic mold is involved in the sale of a home, I am frequently asked, “what is the one thing we need to do to correct the attic mold problem”? Unfortunately, it is usually never one thing causing the mold, but instead is a combination of multiple contributors.
Usually, excess moisture enters the attic through the ceiling, utility chases, electrical fixtures, missing or improperly installed insulation, and the attic entry way. This warm moist air is condensing on the colder roof structures during the fall, winter, and spring months. Without proper ventilation, excess moisture cannot be carried away.
Mold in the attic is typically caused by the intrusion of warm moist air due to elevated humidity in the living space from:
1. Cooking and showers;
2. Gas appliances;
3. Excess humidity from clothes dryers;
4. Fish tanks and plants;
5. Wet basements including open sump pump pits, dirt
basements, and foundation cracks;
6. Efflorescence caused by water infiltration into the basement
usually due to improper yard grading;
7. Inadequate ventilation in the attic due to:
A) Blocked, missing, or undersized soffit vents;
B) Blocked, missing, or undersized ridge vent; and,
C) Blocked, missing, or damaged soffit vent chutes.
8. Leaking ductwork due to improperly installed HVAC systems;
9. The bathroom fan venting into the attic or soffit;
10.Excessive or improperly installed insulation including a
missing vapor barrier;
11. A missing attic staircase cover;
12. Open chasses around the plumbing, light fixtures, or
13. A lack of solar drying (trees and shrubs);
14. Roofing, vent pipe flashing, and chimney flashing leaks;
15. Plumbing and heating system leaks; and,
16. Ice dams.
If you are a homeowner, ask yourself this question. Have I done anything to upset the balance of my home’s operating systems? Have you,
1. Upgraded the heating system?
2. Installed replacement windows?
3. Added insulation?
4. Added new siding?
5. Removed trees or shrubs?
If you have replaced something original to the home or from when you purchased the house, it may have impacted the way your home currently functions.